Ironman Bike Pace Guidelines

Ironman Bike Pace Guide. How to ride strongly and then run faster than ever.By Phil Mosley

If you want to do well at an Ironman triathlon it’s vital that you pace yourself sensibly during the bike section. Once your legs get too sore from riding hard you have almost no chance of running well afterwards. There is no going back from this point - the run section will feel like purgatory.

Therefore your goal is to ride at the fastest Ironman pace that still enables you to run well afterwards. In other words, don't focus too much on being a hero and posting a super fast bike split. If you ride too fast, the chances are you'll undo all your hard work by not being able to run properly afterwards. ​Riding at the right intensity takes discipline and courage especially when other people are overtaking you, but it really works. At around the 80-mile point you'll notice people starting to drop off while you continue to ride strongly, overtaking people as you go.

You'll also find that pacing yourself sensibly helps you to digest your energy drinks and snacks far easier, which helps you maintain your energy levels going into the run.

Intelligent pacing leads to faster, more consistent Ironman results. And yet hardly anyone gets it right. I just hope this feature helps you make the right pacing choices at your next Ironman.

The guidelines below will help you establish your optimal race-day Ironman bike intensity, so that you ride the best time possible while still saving your legs for the run.

Finally, remember that it's crucial to base your Ironman race pace on recent training and race data, such as an FTP test (see guidelines below). Don’t be overoptimistic about your race pace or simply guess it. This is the path to failure.

Ironman Bike Pace Guidelines

​8 to 9 hour Ironman athletes

Power: 78 to 80% of Functional Threshold Power (FTP)

Heart Rate: 81-84% of max bike heart rate

Feel: 5.5 out of 10

9 to 10 hour Ironman athletes

Power: 76-78% of FTP

Heart Rate: 79-82% of your max bike heart rate

Feel: 5 out of 10

10 to 11 hour Ironman athletes

Power: 74-76% of FTP

Heart Rate: 78-80% of your max bike heart rate

Feel: 4.5 out of 10

11 to 12 hour Ironman athletes

Power: 72-74% of FTP

Heart Rate: 76-78% of your max bike heart rate

Feel: 4 out of 10

12 to 13 hour Ironman athletes

Power: 70-72% of FTP

Heart Rate: 75-77% of your max bike heart rate

Feel: 4 out of 10

13 to 14 hour Ironman athletes

Power: 68-70% of FTP

Heart Rate: 74-76% of your max bike heart rate

Feel: 3.5 out of 10

14 to 15 hour Ironman athletes

Power: 66 to 68% of FTP

Heart Rate: 73-75% of your max heart rate

Feel: 3 out of 10

15 to 17 hour Ironman athletes

Power: 64-66% of FTP

Heart Rate: 72-74% of your max heart rate

Feel: 3 out of 10

How To Test Your FTP

Functional Threshold Power (FTP) is the gold standard measure for cycling performance. It’s useful in all types of events from sprint triathlons all the way through to multi-stage cycle races like the Tour De France.

FTP is essentially a measure of the best average power output you can sustain for 1 hour in a time-trial scenario.

To test your FTP you can conduct a simple 20-minute time trial, known as a "CP20" test.

1. You simply ride as hard as you can for 20-minutes and record your average power. This is your CP20 power output.

2. Once you know your CP20 power output you can work out your FTP. Simply multiply your CP20 power output by 95% to get your FTP. ​​Example:If your CP20 power = 200 wattsYou would multiply it by 95% to get your FTP.Therefore, your FTP would be 190 watts. ​